BOSTON — Floating some 200 miles above Earth in the vacuum of space, the astronauts aboard the Russian space station Mir can't just call the orbital equivalent of AAA when something goes awry.
As the list of glitches on the damaged craft grows, Mir has become more a proving ground for astronauts' mechanical ingenuity than a facility for research. In their efforts to cope with an estimated 1,500 malfunctions, cosmonauts have frequently scrapped the owner's manual and high-tech apparatus in favor of duct tape and carpenter's tools. Oxygen canisters have been opened by pounding nails into them. Stubborn hatches are unsealed with screwdrivers.
"The Russian cosmonauts have always been very pragmatic. They can make things work in ways that most people wouldn't think of," says NASA spokesman Steve Nesbitt. "In spite of the claims that Mir has reached the end of its orbital lifetime, they manage to keep it running with just persistence."
Such anecdotes highlight the differences between the American and Russian approach to the dangerous environment of space. While Americans generally have the luxury of relying on "Operation Fail Safe," a protocol in which every essential system on a spacecraft is backed up by two others, the resourceful Russians have learned to get by on less, often by simply improvising.
As such, the events of recent weeks offer a window on the kind of skills and training likely to be most useful on the international Alpha space station, scheduled to begin construction in 1998, or any future attempts to colonize Mars.
So far, the astronauts aboard Mir have coped. But the explosion of an on-board oxygen tank in February coupled with the crashing of an orbital supply ship in June, and the recent accidental disconnection of the ship's computer system have tested the Russians' famed improvisational skills.
Early in the race for space and the moon, Americans possessed a similar attitude, but safety, particularly in the wake of the 1986 Challenger disaster, has made the US space program more cautious.
"It's probably more appropriate to be handy with duct tape and a wrench on a space station - which is pieced together - than on a delicate vehicle like the shuttle where you have only seconds to react after liftoff and during reentry," says Dan Hart, a systems engineering specialist at McDonnell-Douglas who has frequently worked with NASA. "If you screw up on the space station you can usually function for a while, but if something goes wrong with a transportation vehicle at a crucial phase of the mission, you're probably not going to make it home."
At what price?
Mr. Hart adds that the Russians have become extremely competent at ad-libbing repairs partially because they have taken a fiscally frugal stance on building space facilities and have adhered to a more daring philosophy of risk-taking. "We are more constrained today when it comes to protecting human life whereas the Russians are less averse to risks," Hart says.
American missions have the reputation of being overly engineered, tightly controlled, and needlessly costly. Each shuttle has its own group of experts who work with astronauts on the ground. And materials specialists assigned to every inch of a spacecraft know, for example, not only how a sheet of aluminum was installed but where it was mined and the nuances of its composition.
"We don't like to leave any room for error," says Mr. Nesbitt. "We try to be very meticulous...."
Normally, preflight preparation yields invaluable dividends: Astronauts undergo psychological testing, work behind simulators that re-create a rocket ride, perform tasks underwater, and study the function of equipment for four years prior to launch. But it doesn't teach spontaneity.
Midway through Gemini 8, Neil Armstrong - who would later be the first astronaut to walk on the moon - encountered a perilous mishap that could easily have resulted in his death.
He lost control of his craft after a thruster misfired, forcing him to wrest control of the spacecraft as it spun head-over-heel at one revolution per second. Remaining calm, he succeeded in averting tragedy.
Nesbitt says that short of a total communication blackout, astronauts in trouble are never alone in confronting danger. The most publicized near-disaster occurred on Apollo 13, when experts at mission control taught crew members how to manufacture a cabin air filter out of unrelated material found on board.
Loren Acton, a payload specialist aboard the eighth flight of Challenger - two missions before the shuttle exploded over the Atlantic shortly after liftoff - praises the Russians' resourcefulness.
Ms. Acton, today a consultant and professor at Montana State University in Bozeman, Mont., says a major challenge confronting the present and future crews on Mir is keeping track of all the repairs, modifications, and piecemeal additions made to the structure over the course of its 11-year life.
"The Russians have got challenges we have never faced and we should respect them for how well they've done," Acton says. "With any craft or space station, the configuration of your structure is the starting place for any contingency, but it's vitally important that you know what you've got. This will be the biggest difficulty facing those who use space station Alpha."
NASA has a rigid and formal procedure for documenting changes while the Russians, who routinely spend months in space, have passed on information via word of mouth.
Following the return of a recent voyage, a Mir cosmonaut complained of losing his voice after spending hours telling the next team what they should expect to find. Acton notes that the ability to think creatively in completing repairs wanes on long missions with high levels of physical and psychological stress.
"The better trained you are, the more casual you will be in the face of crisis," Nesbitt says. Still, US astronaut-passenger Michael Foale had expressed enthusiasm for mounting a Mir repair effort because it could improve America's knowledge of how to cope with obstacles. The current plan for fixing Mir is to wait for two new cosmonauts to arrive in early August. Mr. Foale would not take part in the repairs.
Yet some experts say the Mir crew may be its own worst enemy. "It seems to be that the present crew on Mir has had a lot of problems, most of them self-inflicted," suggests Thomas Donahue, a professor of atomic physics at the University of Michigan in Ann Arbor. "It appears to be a people problem rather than a hardware problem. Over the course of both the Rus-sian and American space programs, there have been instances where crews have practically mutinied," he says.
"Once the cosmonauts get overstressed, they make mistakes."
Mr. Donahue, who has been involved with the US space program since its genesis in the 1950s, believes that manned missions create an undue burden. After manned missions reached the moon, they are no longer necessary, he adds. Programs such as the space shuttle are costly, risky, and given the returns, less justifiable to a spendthrift Congress and an American public that feels it is overtaxed.
This is why Donahue and other observers believe the estimated $400 million per shuttle voyage and the tens of billions of dollars spent erecting a new international space station could be better used underwriting unmanned explorations of the solar system.
"Because of the problems the Russians are having with Mir and because of the state of their finances, I consider them to be very weak partners," he says.
Donahue says the best example is to contrast the relatively low cost of the current Pathfinder mission to Mars - roughly half that of a shuttle mission - with Mir's troubles. The craft's various setbacks have prevented astronauts from pursuing any useful science other than keeping themselves alive.
Defenders of manned flights respond that they have proved to be extremely valuable in repairing such things as satellites and the Hubbell telescope. Even with the best, most-advanced machines, they say that space still has a place for the tender touch of a human hand.